Updated 5:18 PM ET
(AP) KODIAK, Alaska - Two Coast Guard members were fatally shot at a communications station on an island off Alaska, officials said Thursday.
Officials said it remained unclear if the deaths at the Coast Guard Station on Kodiak Island were a double homicide or a murder-suicide. Capt. Jesse Moore said it was "possible that the suspect remains at large."
Moore told KMXT-FM radio that the shootings happened earlier Thursday.
The station serves as the "ears in the sky" for radio transmissions from mariners and aircraft, Petty Officer Charly Hengen said, and is responsible for relaying distress calls to the air station of the Coast Guard in Anchorage. A commanding officer and enlisted and civilian personnel are stationed at the base about eight miles from the island's largest city of Kodiak, Hengen said.
Officials said the base and nearby schools were on lockdown. Moore told the city's 6,300 or so residents "to remain vigilant and to report any suspicious activity to local law enforcement officials" until more details emerge.
Moore called the shooting a "rare occurrence."
Hengen said the communications station has "secure front doors" and requires its 59 staff members and any visitors to show identification.
Rear Adm. Thomas Ostebo, the commander of Coast Guard operations in Alaska, was in New London, Conn., for a conference at the Coast Guard Academy but left ahead of schedule and could not be reached for comment, according to academy spokesman David Santos. The two-day conference on leadership for the Arctic began earlier Thursday.
The shooting occurred almost 11 years after another fatal shooting involving the Coast Guard on another Alaska island, St. Paul Island, which is about 660 miles west of the city of Kodiak. Chief Warrant Officer Timothy Harris was killed in a shooting by a man he believed was having an affair with his estranged wife.
The FBI said agents were headed to Kodiak from Anchorage about 250 miles away.
The Guard said the identities of the victims would be released after family members were notified.